Stop folder when running out of disk space (fixes #2057)

& tweaks by calmh

lib/config/config.go

@@ -26,7 +26,7 @@ import (
 
 const (
 	OldestHandledVersion = 5
-	CurrentVersion       = 10
+	CurrentVersion       = 11
 	MaxRescanIntervalS   = 365 * 24 * 60 * 60
 )
 
@@ -74,6 +74,7 @@ type FolderConfiguration struct {
 	RescanIntervalS int                         `xml:"rescanIntervalS,attr" json:"rescanIntervalS"`
 	IgnorePerms     bool                        `xml:"ignorePerms,attr" json:"ignorePerms"`
 	AutoNormalize   bool                        `xml:"autoNormalize,attr" json:"autoNormalize"`
+	MinDiskFreePct  int                         `xml:"minDiskFreePct" json:"minDiskFreePct"`
 	Versioning      VersioningConfiguration     `xml:"versioning" json:"versioning"`
 	Copiers         int                         `xml:"copiers" json:"copiers"` // This defines how many files are handled concurrently.
 	Pullers         int                         `xml:"pullers" json:"pullers"` // Defines how many blocks are fetched at the same time, possibly between separate copier routines.
@@ -364,6 +365,9 @@ func (cfg *Configuration) prepare(myID protocol.DeviceID) {
 	if cfg.Version == 9 {
 		convertV9V10(cfg)
 	}
+	if cfg.Version == 10 {
+		convertV10V11(cfg)
+	}
 
 	// Hash old cleartext passwords
 	if len(cfg.GUI.Password) > 0 && cfg.GUI.Password[0] != '$' {
@@ -460,6 +464,14 @@ func ChangeRequiresRestart(from, to Configuration) bool {
 	return false
 }
 
+func convertV10V11(cfg *Configuration) {
+	// Set minimum disk free of existing folders to 1%
+	for i := range cfg.Folders {
+		cfg.Folders[i].MinDiskFreePct = 1
+	}
+	cfg.Version = 11
+}
+
 func convertV9V10(cfg *Configuration) {
 	// Enable auto normalization on existing folders.
 	for i := range cfg.Folders {

lib/config/config_test.go

@@ -92,6 +92,7 @@ func TestDeviceConfig(t *testing.T) {
 				Pullers:         16,
 				Hashers:         0,
 				AutoNormalize:   true,
+				MinDiskFreePct:  1,
 			},
 		}
 		expectedDevices := []DeviceConfiguration{

lib/config/wrapper.go

@@ -96,6 +96,10 @@ func Load(path string, myID protocol.DeviceID) (*Wrapper, error) {
 	return Wrap(path, cfg), nil
 }
 
+func (w *Wrapper) ConfigPath() string {
+	return w.path
+}
+
 // Stop stops the Serve() loop. Set and Replace operations will panic after a
 // Stop.
 func (w *Wrapper) Stop() {

lib/model/model.go

@@ -45,6 +45,7 @@ const (
 	indexBatchSize         = 1000       // Either way, don't include more files than this
 	reqValidationTime      = time.Hour  // How long to cache validation entries for Request messages
 	reqValidationCacheSize = 1000       // How many entries to aim for in the validation cache size
+	minHomeDiskFreePct     = 1.0        // Stop when less space than this is available on the home (config & db) disk
 )
 
 type service interface {
@@ -1230,6 +1231,10 @@ func (m *Model) internalScanFolderSubs(folder string, subs []string) error {
 		return errors.New("no such folder")
 	}
 
+	if err := m.CheckFolderHealth(folder); err != nil {
+		return err
+	}
+
 	_ = ignores.Load(filepath.Join(folderCfg.Path(), ".stignore")) // Ignore error, there might not be an .stignore
 
 	// Required to make sure that we start indexing at a directory we're already
@@ -1658,6 +1663,10 @@ func (m *Model) BringToFront(folder, file string) {
 // CheckFolderHealth checks the folder for common errors and returns the
 // current folder error, or nil if the folder is healthy.
 func (m *Model) CheckFolderHealth(id string) error {
+	if free, err := osutil.DiskFreePercentage(m.cfg.ConfigPath()); err == nil && free < minHomeDiskFreePct {
+		return errors.New("out of disk space")
+	}
+
 	folder, ok := m.cfg.Folders()[id]
 	if !ok {
 		return errors.New("folder does not exist")
@@ -1673,6 +1682,8 @@ func (m *Model) CheckFolderHealth(id string) error {
 			err = errors.New("folder path missing")
 		} else if !folder.HasMarker() {
 			err = errors.New("folder marker missing")
+		} else if free, errDfp := osutil.DiskFreePercentage(folder.Path()); errDfp == nil && free < float64(folder.MinDiskFreePct) {
+			err = errors.New("out of disk space")
 		}
 	} else if os.IsNotExist(err) {
 		// If we don't have any files in the index, and the directory

lib/model/rwfolder.go

@@ -437,6 +437,7 @@ func (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
 	// !!!
 
 	changed := 0
+	pullFileSize := int64(0)
 
 	fileDeletions := map[string]protocol.FileInfo{}
 	dirDeletions := []protocol.FileInfo{}
@@ -485,6 +486,7 @@ func (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
 		default:
 			// A new or changed file or symlink. This is the only case where we
 			// do stuff concurrently in the background
+			pullFileSize += file.Size()
 			p.queue.Push(file.Name, file.Size(), file.Modified)
 		}
 
@@ -492,6 +494,17 @@ func (p *rwFolder) pullerIteration(ignores *ignore.Matcher) int {
 		return true
 	})
 
+	// Check if we are able to store all files on disk
+	if pullFileSize > 0 {
+		folder, ok := p.model.cfg.Folders()[p.folder]
+		if ok {
+			if free, err := osutil.DiskFreeBytes(folder.Path()); err == nil && free < pullFileSize {
+				l.Infof("Puller (folder %q): insufficient disk space available to pull %d files (%.2fMB)", p.folder, changed, float64(pullFileSize)/1024/1024)
+				return 0
+			}
+		}
+	}
+
 	// Reorder the file queue according to configuration
 
 	switch p.order {

lib/osutil/osutil.go

@@ -16,6 +16,7 @@ import (
 	"runtime"
 	"strings"
 
+	"github.com/calmh/du"
 	"github.com/syncthing/syncthing/lib/sync"
 )
 
@@ -210,3 +211,13 @@ func init() {
 func IsWindowsExecutable(path string) bool {
 	return execExts[strings.ToLower(filepath.Ext(path))]
 }
+
+func DiskFreeBytes(path string) (free int64, err error) {
+	u, err := du.Get(path)
+	return u.FreeBytes, err
+}
+
+func DiskFreePercentage(path string) (freePct float64, err error) {
+	u, err := du.Get(path)
+	return (float64(u.FreeBytes) / float64(u.TotalBytes)) * 100, err
+}

lib/osutil/osutil_test.go

@@ -164,3 +164,18 @@ func TestInWritableDirWindowsRename(t *testing.T) {
 		}
 	}
 }
+
+func TestDiskUsage(t *testing.T) {
+	free, err := osutil.DiskFreePercentage(".")
+	if err != nil {
+		if runtime.GOOS == "netbsd" ||
+			runtime.GOOS == "openbsd" ||
+			runtime.GOOS == "solaris" {
+			t.Skip()
+		}
+		t.Errorf("Unexpected error: %s", err)
+	}
+	if free < 1 {
+		t.Error("Disk is full?", free)
+	}
+}